Project 1 is the main contraceptive development project for the BUSM CRC. The overarching goal of Project 1 is to deliver a Human Contraceptive Antibody (HCA) and prototype HCA-intravaginal ring (HCA-IVR) that are ready for human clinical trials. In the first year of the project we will work closely with Mapp Biopharmaceutical (Antibody Industrialization Core) to test HCA IgG1 and engineered variants of HCA for contraceptive efficacy in sperm agglutination and motility assays. Based on the results of these studies, we will select lead HCA candidates showing maximum efficacy to undergo further testing in additional sperm function assays assessment for toxicity/inflammation in a human vaginal epithelium model. Our lead HCA (HCA*) will be selected based on performance in sperm function tests and the safety evaluation. In subsequent years of the project, HCA* will be manufactured by the Antibody Industrialization Core and incorporated into an IVR specifically designed for the purpose of sustained release of HCA*. The HCA*-IVR will undergo preclinical testing in a macaque model to assess safety, PK, ex vivo efficacy and antibody and sperm distribution in the lower genital tract.